# Electric Current

by Ron Kurtus (15 November 2019)

Electric current is the movement or flow of electrically charged particles around an electric circuit, often in a metal wire. Those particles are usually electrons, although there are some situations where the current consists of positive charged (+) ions in an electrolyte material.

The SI unit of electric current is the ampere (A).

The flow of charged particles may be in one direction, such as in direct current (DC) electricity or alternating directions as in alternating current (AC) electricity.

By convention, electric current moves from the positive terminal to the negative. However, the flow of electrons is from negative to positive.

Questions you may have include:

• What is the definition of an ampere?
• What is the convention for current flow?
• What is the convention for flow of electrons?

This lesson will answer those questions. Useful tool: Units Conversion

## Ampere is unit of current

The ampere (A) is the standard unit of electric current. It is a measure of the rate that electric charges pass a given point in an electric circuit per second.

One ampere equals 6.241*1018 electrons passing a point per second or one coulomb per second. (The coulomb (C) is the SI unit of electric charge.)

## Current Flow Convention

The convention is that current is the flow of electric charges around a circuit from the positive source terminal to the negative.

This was the convention chosen during the discovery of electricity in which the direction of electric current was thought to flow in a circuit.

## Electron Current Flow

The flow of electrons around the circuit is opposite to the direction of the conventional current flow and is negative to positive. For example, the electrons flow from the negative pole of the battery (the cathode) and return back to the positive pole (the anode) of the battery.

This is because the charge on an electron is negative by definition and so is attracted to the positive terminal. This flow of electrons is called Electron Current Flow.

## Summary

Electric current is the movement or flow of electrically charged particles around an electric circuit.

The SI unit of electric current is the ampere (A).

By convention, electric current moves from the positive terminal to the negative. However, the flow of electrons is from negative to positive.

## Resources and references

Ron Kurtus' Credentials

### Websites

Electric current - Wikipedia

DC and AC Electricity Resources

Physics Resources

### Books

Teach Yourself Electricity and Electronics by Stan Gibilisco; McGraw-Hill; (2001) \$34.95 - Guide for professionals, hobbyists and technicians desiring to learn AC and DC circuits

Do you have any questions, comments, or opinions on this subject? If so, send an email with your feedback. I will try to get back to you as soon as possible.

## Students and researchers

www.school-for-champions.com/science/
electric_current.htm

## Where are you now?

School for Champions

Physics topics

## Also see

### Let's make the world a better place

Be the best that you can be.

Use your knowledge and skills to help others succeed.

Don't be wasteful; protect our environment.

### Live Your Life as a Champion:

Seek knowledge and gain skills

Do excellent work

Be valuable to others

Have utmost character

#### Be a Champion!

The School for Champions helps you become the type of person who can be called a Champion.